dotSCAD/docs/lib3x-shape_path_extend.md

shape_path_extend

It extends a 2D stroke along a path to create a 2D shape. This module is suitable for a path created by a continuous function. The returned points can be used with xxx_extrude modules of dotSCAD. The shape points can be also used with the built-in polygon module.

When using this function, you should use points to represent the 2D stroke.

Parameters

• stroke_pts : A list of points represent a stroke. See the example below.
• path_pts : A list of points represent the path.
• scale : Scales the 2D shape by this value over the length of the extension.
• closed : If the first point and the last point of path_pts has the same coordinate, setting closed to true will connect them automatically.

Examples

use <shape_path_extend.scad>
use <shape_circle.scad>
use <archimedean_spiral.scad>

$fn = 96;

stroke1 = [[-5, 2.5], [-2.5, 0], [0, 2.5], [2.5, 0], [5, 2.5]];
path_pts1 = shape_circle(50, 60);
polygon(
    shape_path_extend(stroke1, path_pts1)
);


stroke2 = [[-4, 0], [0, 4], [4, 0]];
pts_angles = archimedean_spiral(
    arm_distance = 17,
    init_angle = 180,
    point_distance = 5,
    num_of_points = 85 
); 

translate([120, 0, 0]) 
    polygon(
        shape_path_extend(
            stroke2, 
            [for(pa = pts_angles) pa[0]]
        )
    );

use <bezier_curve.scad>
use <shape_path_extend.scad>
use <path_extrude.scad>
	
t_step = 0.1;
width = 2;

p0 = [0, 0];
p1 = [40, 60];
p2 = [50, 90];
p3 = [0, 200];

path = bezier_curve(t_step, 
	[p0, p1, p2, p3]
);

stroke = [[-5, 2.5], [-2.5, 0], [0, 2.5], [2.5, 0], [5, 2.5]];

path_extrude(
	shape_path_extend(stroke, path, scale = 5), 
	path,
	scale = 0.1
);